Add information about x86 support to the README.md file

Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Change-Id: I0b5e0a279d16eaa69db39d4786e95d9cce0cc79b
diff --git a/README.md b/README.md
index 4e07685..7453de6 100644
--- a/README.md
+++ b/README.md
@@ -297,6 +297,11 @@
     OPENBMC_HOST=x.x.x.x  LOOP_TEST_COMMAND="tests/test_fw_version.robot" ITERATION=5 OPENBMC_SYSTEMMODEL=witherspoon tox -e witherspoon -- ./extended/full_suite_regression.robot
     ```
 
+* Host CPU architecture
+
+    By default openbmc-test-automation framework assumes that host CPU is based on the POWER architecture.
+    If your host CPU is x86 add `-v PLATFORM_ARCH_TYPE:x86` variable setting to your CLI commands.
+
 **Jenkins jobs tox commands**
 * HW CI tox command:
     ```